1. Change of State

2. A change of state is the conversion of a substance from one physical form to another

3. Water to….

4. Steam!

5. When matter changes state, the components of the item remains the same.

6. Can you think of a type of matter that changes state from one form to another?

7. Energy and Change of State

8. When a substance change state, the energy of that substance also changes.

9. The energy of a substance is determined by the motion of its particles.

10. Example: gas-lots of motion= lots of energy

11. The faster particles move, the more energy a substance has.

12. This works in reverse too, The slower particles move, the less energy the matter has.

13. What happens to the energy of molecules when a liquid freezes?

14. Melting

15. Melting is the change of state from a solid to a liquid.

16. Example: a candle melts into liquid wax

17. The point where a solid turns into a liquid is called the melting point.

18. The melting point of a substance will not change- no matter if you have a pinch of sugar or a full bag of it.

19. Melting can be called an endothermic change because energy gets absorbed by the change of state.

20. Can you describe another endothermic change?

21. Freezing

22. Freezing is the change of state from a liquid to a solid.

23. Example: put liquid “pop-ice” in the freezer- within a few hours it will be a solid!

24. The point at which a liquid turns into a solid is called the freezing point.

25. Freezing can also be called an exothermic change because energy is removed by the change of state

26. Can you think of another exothermic change?

27. Vaporization

28. Vaporization is the change of state from a liquid to a gas.

29. Boiling is when vaporization occurs from boiling liquid.

30. Evaporation is when vaporization occurs at a surface of a liquid below its boiling point.

31. Pressure can affect the boiling point and vaporization of a liquid. The higher elevation you are, the lower the boiling point will be of a liquid.

32. Vaporization is an endothermic change of state.

33. Condensation

34. Condensation is the change of state from a gas to a liquid

35. Condensation can occur when you put a cold lid on a pot of boiling water. It also occurs when the mirror in your bathroom steams up after a shower.

36. Condensation is an exothermic change of state.

37. Why is condensation an exothermic change?

39. Endothermic Heat Energy is required Exothermic Heat Energy is removed

40. Types of vaporization Boiling Occurs throughout liquid Evaporation Occurs at surface of liquid

41. Change of state From..toEnergy

42. Change of state From..toEnergy